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PR created: #39879

Hi @engcom-Hotel. Thank you for working on this issue.
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Hello @Genaker,

Thanks for the report and collaboration!

I've analyzed this issue thoroughly. It appears that there's a problem with the LIKE condition (when in uppercase) not functioning properly in Magento's order collection filtering.

We have tried to reproduce the issue in the latest development i.e. 2.4-develop via making a sample script as below;

use Magento\Framework\App\Bootstrap;
require __DIR__ . '/app/bootstrap.php';

$bootstrap = Bootstrap::create(BP, $_SERVER);
$objectManager = $bootstrap->getObjectManager();

// Get order grid collection
$collection = $objectManager->create(\Magento\Sales\Model\ResourceModel\Order\Grid\Collection::class);

$field = 'customer_email';
$value = 'order_80'; // Replace with the beginning of an email you know exists

// Method 1: Using uppercase 'LIKE'
$collection->addFieldToFilter($field, ['LIKE' => $value . '%']);

echo "SQL Query with UPPERCASE 'LIKE':\n";
echo $collection->getSelectSql(true) . "\n\n";
echo "Results count: " . $collection->count() . "\n\n";

// Reset collection
$collection = $objectManager->create(\Magento\Sales\Model\ResourceModel\Order\Grid\Collection::class);

// Method 2: Using lowercase 'like'
$collection->addFieldToFilter($field, ['like' => $value . '%']);

echo "SQL Query with lowercase 'like':\n";
echo $collection->getSelectSql(true) . "\n\n";
echo "Results count: " . $collection->count() . "\n\n";

The output for the same is as follows:

SQL Query with UPPERCASE 'LIKE':
SELECT `main_table`.* FROM `sales_order_grid` AS `main_table` WHERE (((`main_table`.`customer_email` = 'order_80%')))

Results count: 0

SQL Query with lowercase 'like':
SELECT `main_table`.* FROM `sales_order_grid` AS `main_table` WHERE (`main_table`.`customer_email` LIKE 'order_80%')

Results count: 1

The issue seems reproducible for us. Hence confirming the issue.

Thanks